flatgrinder or anyone else,
Can you explain the pros and cons of grinding edge down versus edge up?
Thanks!
Seems to me that 95+% of makers grind edge up, it's easier to focus on the edge thickness this way -but the plunges are usually straight or perpendicular to the edge.
The others grind edge down and make knives that have a sweeping plunge ... I guess they're watching the sweep. I haven't tried it yet, but would like to. Theoretically, sweeping plunges should be stronger if done right.
I guess it could be compared to milling: grinding edge down is like "conventional" milling, it's easier on the belt .... grinding edge up is like "climb" milling -more likely to shear off grit and wear the belt down faster, that's why most makers who grind edge up cut a 45 degree bevel first with a worn out belt.
Basically, in my personal opinion, it seems like grinding edge down has more benefits: grinding belt life and a stronger knife?
However, it requires a lot more skill and control -especially on a big ol' Olympic Square Wheel type grinder with a 4" wide wheel on full speed!!
If memory serves me right, Rod primarily learnt from Harvey Draper (I think he told me, he spent a week with him and after that he was ready, he purchased several thousand pounds of 440C from Fry steel and practiced for several months developing his own grinding style).
Rod was also a knife customer of Gil Hibben (I can't remember if he said he learnt from Gil too) and he also spent time with Bill Moran.
Here's Gil grinding edge down:
http://www.youtube.com/watch?v=iRV4GmGZnBg
(Bill Luckett in Texas also grinds with the sweep -but I don't think he learned from Rod. He's also been making knives a long time).
Hope this info's interesting.